This section provides background information related to the present disclosure which is not necessarily prior art.
A significant problem in the production and use of polyurethane resins is the disposal of thermally degraded and/or off-grade, polyurethane resins. For example, when a thermoplastic polyurethane (TPU) material is incorporated into various products or used to form products, waste material is generated. The waste material includes fully or partially thermally degraded resins, misformulated resins, or scrap resins. Much of the waste material with polyurethane in sheet form is the scrap edges from polyurethane materials that have been shaped using a mold. Although many efforts have been made to shape molds to minimize waste, the nature of using sheets of TPU necessarily generates scrap edges.
In prior systems, the waste material was discarded because it was not suitable for use in the original product. In still other systems, the scrap resin or misformulated resins was separated into small pieces, to form regrind, and the regrind was blended with virgin resin and used in the same application. Regretfully, only a limited amount of regrind can be used without sacrificing the desired properties of the particular polyurethane resin for the application.
Using regrind to provide different parts of an item or for use in a new item would reduce the need to create virgin thermoplastic polyurethane. Modifications to regrind use would provide alternatives to allow the scrap polyurethane from one component of a product to be used in a different component of the product or in a different product. Such modifications are environmentally friendly, beneficial in a production line, increase cost-effectiveness, minimize downtime and loss of plant resources, and minimize the need to produce and purchase virgin materials.